1. Field of the Invention
This invention relates to the recovery of tertiary butyl alcohol. More particularly, this invention relates to a method for enhancing the yield of tertiary butyl alcohol during a tertiary butyl alcohol recovery process. Still more particularly, this invention relates to a method for the manufacture and recovery of tertiary butyl alcohol wherein an enhanced yield of tertiary butyl alcohol is obtained during the recovery process.
2. Background Information
Tertiary butyl alcohol can be recovered by distillation from a tertiary butyl hydroperoxide reaction product comprising oxygen-containing compounds, including tertiary butyl alcohol, unreacted tertiary butyl hydroperoxide, oxygen-containing by-products such as ditertiary butyl peroxide, allyl tertiary butyl peroxide, isopropyl hydroperoxide, etc. and water.
Methyl tertiary butyl ether (MTBE) can be prepared by the catalytic reaction of tertiary butyl alcohol (TBA) with methanol. Normally, an excess of methanol is used.
It is known that tertiary butyl alcohol and propylene oxide can be prepared by the molybdenum-catalyzed reaction of propylene with tertiary butyl hydroperoxide.
3. Prior Art
Kollar U.S. Pat. No. 3,351,635 discloses the reaction of tertiary butyl hydroperoxide with propylene to provide a reaction product comprising unreacted propylene, propylene oxide, and tertiary butyl alcohol. Related processes are disclosed, for example, in Marquis et al U.S. Pat. No. 4,845,251 and Marquis et al U.S. Pat. No. 4,891,437.
Grane et al. U.S. Pat. No. 4,296,262 is representative of patents directed to the manufacture and recovery of tertiary butyl alcohol by the thermal decomposition of tertiary butyl hydroperoxide.
Grane et al. U.S. Pat. No. 4,294,999 and Sanderson et al. U.S. Pat. No. 4,922,036 are representative of patents directed to the manufacture and recovery of tertiary butyl alcohol by the catalytic decomposition of tertiary butyl hydroperoxide.
Rao et al. U.S. Pat. No. 4,144,138, Kruse et al. U.S. Pat. No. 5,243,091, Knifton et al. U.S. Pat. No. 4,822,921 and Gupta U.S. Pat. No. 5,292,964, are representative of patents directed to the manufacture and recovery of methyl tertiary butyl ether by the catalytic reaction of methanol with tertiary butyl alcohol.
In all of these processes a tertiary butyl hydroperoxide reaction product is obtained comprising tertiary butyl alcohol, unreacted tertiary butyl hydroperoxide and reaction products boiling below tertiary butyl alcohol, such as water, ditertiary butyl peroxide, tertiary butyl hydroperoxide, allyl tertiary butyl peroxide, etc.
It is conventional to recover tertiary butyl alcohol from a tertiary butyl hydroperoxide reaction product by distillation in a distillation zone comprising a plurality of distillation columns, including a vacuum distillation column to which a tertiary butyl alcohol fraction is charged and in which it is separated into a vaporized overhead tertiary butyl alcohol fraction and a lower boiling liquid fraction comprising unreacted tertiary butyl hydroperoxide and reaction by products boiling below tertiary butyl alcohol.